Metamath Proof Explorer


Theorem 1iscard

Description: 1 is a cardinal number. (Contributed by RP, 1-Oct-2023)

Ref Expression
Assertion 1iscard ⊢ 1 𝑜 ∈ ran ⁡ card

Proof

Step Hyp Ref Expression
1 omssrncard ⊢ ω ⊆ ran ⁡ card
2 1onn ⊢ 1 𝑜 ∈ ω
3 1 2 sselii ⊢ 1 𝑜 ∈ ran ⁡ card